Uniform polypyrrole (PPy) nanoparticles were fabricated from a facile one-step aqueous dispersion polymerization. Owing to their high photothermal conversion efficiency and photostability compared with the well-known Au nanorods, as well as their good colloidal stability and biocompatibility, the resulting PPy nanoparticles could be used as a novel promising photothermal ablation coupling agent for targeted treatment of cancer.